/*---------------------------------------------------------------------------*\
  =========                 |
  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
   \\    /   O peration     |
    \\  /    A nd           | Copyright (C) 2011 OpenFOAM Foundation
     \\/     M anipulation  |
-------------------------------------------------------------------------------
License
    This file is part of OpenFOAM.

    OpenFOAM is free software: you can redistribute it and/or modify it
    under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
    for more details.

    You should have received a copy of the GNU General Public License
    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.

Description
    Searching and marking zones of the patch.

\*---------------------------------------------------------------------------*/

#include "PatchTools.H"

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

// Finds area, starting at faceI, delimited by borderEdge.
// Marks all visited faces (from face-edge-face walk) with currentZone.
template
<
    class BoolListType,
    class Face,
    template<class> class FaceList,
    class PointField,
    class PointType
>

void
Foam::PatchTools::markZone
(
    const PrimitivePatch<Face, FaceList, PointField, PointType>& p,
    const BoolListType& borderEdge,
    const label faceI,
    const label currentZone,
    labelList&  faceZone
)
{
    const labelListList& faceEdges = p.faceEdges();
    const labelListList& edgeFaces = p.edgeFaces();

    // List of faces whose faceZone has been set.
    labelList changedFaces(1, faceI);

    while (true)
    {
        // Pick up neighbours of changedFaces
        DynamicList<label> newChangedFaces(2*changedFaces.size());

        forAll(changedFaces, i)
        {
            label faceI = changedFaces[i];

            const labelList& fEdges = faceEdges[faceI];

            forAll(fEdges, fEdgeI)
            {
                label edgeI = fEdges[fEdgeI];

                if (!borderEdge[edgeI])
                {
                    const labelList& eFaceLst = edgeFaces[edgeI];

                    forAll(eFaceLst, j)
                    {
                        label nbrFaceI = eFaceLst[j];

                        if (faceZone[nbrFaceI] == -1)
                        {
                            faceZone[nbrFaceI] = currentZone;
                            newChangedFaces.append(nbrFaceI);
                        }
                        else if (faceZone[nbrFaceI] != currentZone)
                        {
                            FatalErrorIn
                            (
                                "PatchTools::markZone"
                                "("
                                    "const PrimitivePatch<Face, FaceList, "
                                        "PointField, PointType>& p,"
                                    "const BoolListType& borderEdge,"
                                    "const label faceI,"
                                    "const label currentZone,"
                                    "labelList&  faceZone"
                                ")"
                            )
                                << "Zones " << faceZone[nbrFaceI]
                                << " at face " << nbrFaceI
                                << " connects to zone " << currentZone
                                << " at face " << faceI
                                << abort(FatalError);
                        }
                    }
                }
            }
        }

        if (newChangedFaces.empty())
        {
            break;
        }

        // transfer from dynamic to normal list
        changedFaces.transfer(newChangedFaces);
    }
}


// Finds areas delimited by borderEdge (or 'real' edges).
// Fills faceZone accordingly
template
<
    class BoolListType,
    class Face,
    template<class> class FaceList,
    class PointField,
    class PointType
>

Foam::label
Foam::PatchTools::markZones
(
    const PrimitivePatch<Face, FaceList, PointField, PointType>& p,
    const BoolListType& borderEdge,
    labelList& faceZone
)
{
    faceZone.setSize(p.size());
    faceZone = -1;

    label zoneI = 0;
    for (label startFaceI = 0; startFaceI < faceZone.size();)
    {
        // Find next non-visited face
        for (; startFaceI < faceZone.size(); ++startFaceI)
        {
            if (faceZone[startFaceI] == -1)
            {
                faceZone[startFaceI] = zoneI;
                markZone(p, borderEdge, startFaceI, zoneI, faceZone);
                zoneI++;
                break;
            }
        }
    }

    return zoneI;
}



// Finds areas delimited by borderEdge (or 'real' edges).
// Fills faceZone accordingly
template
<
    class BoolListType,
    class Face,
    template<class> class FaceList,
    class PointField,
    class PointType
>

void
Foam::PatchTools::subsetMap
(
    const PrimitivePatch<Face, FaceList, PointField, PointType>& p,
    const BoolListType& includeFaces,
    labelList& pointMap,
    labelList& faceMap
)
{
    label faceI  = 0;
    label pointI = 0;

    const List<Face>& localFaces = p.localFaces();

    faceMap.setSize(localFaces.size());
    pointMap.setSize(p.nPoints());

    boolList pointHad(pointMap.size(), false);

    forAll(p, oldFaceI)
    {
        if (includeFaces[oldFaceI])
        {
            // Store new faces compact
            faceMap[faceI++] = oldFaceI;

            // Renumber labels for face
            const Face& f = localFaces[oldFaceI];

            forAll(f, fp)
            {
                const label ptLabel = f[fp];
                if (!pointHad[ptLabel])
                {
                    pointHad[ptLabel]  = true;
                    pointMap[pointI++] = ptLabel;
                }
            }
        }
    }

    // Trim
    faceMap.setSize(faceI);
    pointMap.setSize(pointI);
}


// ************************************************************************* //
